Method of and apparatus for dispensing liquefied gas mixtures



Jul 21,1942. WHLTE 2,290,839

METHOD OF AND APPARATUS FOR DISPENSING LIQUEFIED GAS MIXTURES Filed Nov. 26, 1941 Patented July 21, 1942 L 'u-mTEo' STATES PATENST'. OFFICE METHOD OF APPARATUS FOR DISPENS- ING LIQUEFIED GAS MIXTURES Loyd J. White, San Antonio, Tex., assignor to Southern Steel Company, San Antonio, Tex., a corporation of Texas Application November 26, 1941, Serial No. 420,566

This invention relates to a method of and apparatus for vaporizing and dispensing liquefied gas and, among other objects, aims to provide a greatly improved system to dispense propane, ethane or other highly volatile liquefied gases or mixtures thereof combined with normally liquid petroleum distillates or blends thereof, such as commercial gasoline, so that the vapor pressure at normal temperatures is reduced and the necessity to use extraheavy bulk storage tanks,

truck tanks, dispensing containers and other appurtenances is avoided. One of the main objects is to provide an economical and commercially practicable method of using propane as the base fuel in domestic-and commercial gas dispensing installations without requiring heavy and expensive storage, transporting and dispensing equipment due to the normal high vapor pressure of propane when used alone.

It is contemplated that, due to war conditions and the present National Defense Program, there will be a shortage of butane which is employed in underground gas systems of the general type shown in Patent 2,176,829, because butane and other less volatile v more extensively in-the manufacture of high octane aviation fuel. However, some of the more volatile hydrocarbons, such as propane, derived from petroleum and-matural gases, are not so readily adapted to the making of high octane aviation fuel and are therefore readily available.

for use in domestic dispensing systems. Propane is now in general use for household systems, but one of its main drawbacks is the requirement that the containers therefor shall be capable of withstanding very much higher pressures than those-designed for pressures such as for butane mixtures. Further, the cost of transportation of propane is much higher, due to the heavy equipment required to withstand the high pressures. Also, it is well known that propane is not as rich in BTU content as the less volatile mixtures of butane. Due to the shortage of steel available at this time for ordinary civilian use and of other, equipmentused in such systems. it is-hikhly d sirable to reduce the quantity of metals required to be used in systems for dispensing. propane mixtures. Therefore, it is ,one of the main obiets of this invention to provide ,an improved method of and apparatus for dispensing propane and the like which" involves mixing it with a 11-Claims- I (or 62-1) terns, with slight modifications and in improved systems wherein provision is made for removing the gasoline after it has served its purpose. Other aims and advantages of the invention will appear in the specification, when considered ,in connection with the accompanying drawings,

wherein:

Fig. 1 is a longitudinal sectional view of a typical system designed to carry out the method; and 1 Fig. 2 is an enlarged sectional view of a valved fitting for dispensing vapor anddischargins sep- ,arated gasoline. 1

Referring particularly to the illustrative apparatus, the system is shown as embodying a main storage tank III which is buried in the ground to from the surrounding earth; but it is to be understood that the invention is applicable to both underground and aboveground installations. In this instance, the main tank ID has an ordinary. s'tandpipe II, to the upper end of which is connected the usual multiple valved fitting I! like that shown in the aforesaid patent. It embodies a liquid level gauge hydrocarbons are now used normally liquid hydrocarbon fuel, .such as ordinary gasoline, to raise its boiling point and reduce its vapor pressure, the eby making it P05! sible to use such mixtures in existing butane sys l5 leading through a the main 13 which may be of the float operated type as shown or of the slip tube type. It also has the usual filling valve l4 and a-liquid eduction tube valved outlet branch I is it is to be understood that such systems may be either gravity filled or pressure filled.

Liquid from the main tank 10 is adapted to be delivered by its vapor pressure-to a second container, here shown as being an auxiliary tank or extension l'l connected to the main tank; although it will be understood that the second vaporizing container can be entirely separate from tank. It-is also shown as being arranged to absorb vaporizing heat from the surrounding earth. In this instance, the vaporizin tank ll carries a standpipe l8 arranged in the same protecting casing 19 with the main standpipe I I and a liquid eduction pipe 20 is connected to the branch-l6 to discharge into the standpipe. l8 through either of two-pressure reducing regu lators 2i and eduction pipe. when the liquid passes through a pressure reducing regulator and some'of it flashes into vapor due to the reduction in pressure,' ice is likely to form inthe regulator when the mixtures carries a moisture content and, insome. cases, will obstruct th'e valve orifice and prevent the regulator from functioning properly. The

22 connected in .p l'a lf to the l pounds and the otherat 6 out. One of the regulatorsmay be set at, say 8 pounds, so that the liquid will normally flow through the regulator set to close at 8 pounds until it ceases to function. Then, the other regulator will come into action and operate until the first regulator thaws out and resumes operation. It will be understood that more than two regulators may be desirable in extremely cold climates, while in very warm climates one regulator will perform satisfactorily. If the mixture is moisture-free one regulator is all that is required in any climate.

The second standpipe is shown as having a fitting in the form of a cross 23 screwed on its upper end and shown in'detail in Fig. 2. The upper branch of the cross carries a slip tube gauge 24, or a float operated gauge similar to the'gauge I3 may be employed. One of the lateral branches 25 has an upstanding extension 26 in which is mounted a liquid evacuating valve 21 preferably similar to that shown in my application Ser. No. 299,211, filed October 12, 1939. The branch 26 also has a hose fitting 28, so arranged that, when an evacuating hose is connected to it, the valve isautomatically opened. It is designed to evacu- 'ate' liquid or spent gasoline from the bottom of the vaporizing tank H through an eduction tube 29. When a hose is connected the gasoline will be discharged under the pressure existing in the vaporizing tank. Another branch 30 of the cross fitting is shown as having a valve controlled outlet leading through a depending nipple 3| to dispense vapor from the vaporizing tank I! through an ordinary second stage pressure reducing regulator 32 connected to a service pipe 33 preferably extending downwardly to a point adjacent to the tank and laterally underground toward the point of use. In this example, thelow'est point of the service pipe carries a revaporizing spur pipe 34 extending downwardly into the tank It so that any condensate formed in the service pipe will drain into the pipe and be revaporized. However, the'vaporizer may be like that shown in my Patent 2,105,383.

stage pressure reducing regulators, some of it immediately flashes into vapor and, due to the gasoline constituents will not readily vaporize to the fitting 28,

quantity of gasoline may From the foregoing description, it is believed that the method of operation will be apparent; It is contemplated that propane will be mixed at the refinery with less volatile hydrocarbon fuels or blends, such as gasoline. The mixture ratio will be determined by the desired'vapor pressure at normal or atmospheric temperatures and the safe working pressures prescribed for truck tanks and the systems in which the mixture is to be employed. An ordinary mixture of, say propane and 50% gasoline by volume, has been found to be satisfactory'because, its pressure does not exceed the safe working pressure of containers designed for ordinary butane mixtures. The gasoline is readily miscible with propane and not onlyserves to reduce its vapor pressure during transit and in the storage containers, but a small-quantity of it vaporlzes with the propane component and remains mixed with it, thus enriching the propane vapor. The

mixture is charged into the main storage tank liquid passes from it to-the vaporiz-- I0 and the ing chamber ortank II, as gas is consumed. Incidentally, the storage capacity of-the vaporizing tank orchamber I1 is preferably such as to hold all of the gasoline used in the mixture which fills the main storage tank. In the case of a 50-50 mixture, the vaporizing tank should be at least half the-size of the main tank. As the mixture passes through one of the first necting a-hose to the fitting 28.

at any ordinary atmospheric or earth's temperatures. Therefore, the gasoline separates and settles. to the bottom of the vaporizing'chamber. The used gasoline will rise in the chamber and eventually fill it if it is not evacuated. It is contemplated that the used gasoline may beremoved automatically by means of a float operated valve (not shown) or it may be evacuated periodically, preferably when the main tank is filled, by con- The evacuated gasoline may be used in automobiles, gas engines, tractors and the like. The vaporizing tank will be'fully evacuated to the lower end of dip pipe due to the vapor pressure existing in it.

The vapor passes from the vaporizing tank through the usual low pressure regulator at the prescribed pressure for the consuming appliances. Any condensate will collect in the condensate' trap or spur pipe 34 and be revaporized, due to absorption of heat from the. liquid in tank III which, in turn, absorbs heat from the earth below the frost line. a

From the foregoing description, it will be seen that the method and apparatus provide foithe use of propane and its: mixtures with less volatile hydrocarbons and avoid the-necessity for using high pressure equipment for handling it,

thereby efiectinggreat economy in the use of indispensable defense materials. Furthermore, such systems may be buried in the ground in extremely cold climates and the mixture of propane and gasoline maybe varied to suit any given range of temperatures. Moreover, a suflicient be employed in warm climates where the {systems are sometimes placed above ground to avoid the possibility of generating high or dangerous vapor pressures or pressures exceeding the safe limits of tanks and other equipment.

Obviously,-theinvention. is not restricted to the particular embodiment thereof herein shown and described. Moreover, the method can be practiced by employin other types of apparatus.

What .is claimed is:

- 1. In a liquefied gas dispensing system of the character described, a storage container adapted to be'filled with liquefied gas; a liquid eductlon pipe connected to deliver liquid from the storage container; a separate vaporizing chamber into which the liquid is discharge and vaporized: at leasttwo pressure reducing valves connected in parallel to .the liquid eductlon pipe and adjusted to operate at difierent back pressures, so that when one reducing valve ceases to function, due to freezing, the other will function until the first one is thawed out; a vapor discharge conduit connected to the vaporizing tank; and asecond stagepressure reducing regulator connected to the vapor delivery conduit.

2. In a liquefied gas-system'of. the character described, a storage'tank adaptedto be charged with a. mixture of liquefied gas and a normally liquid hydrocarbon fuel to reduce the vapor pressure; a standpipe connected to the tank; valved filling and dispensing appurtenances connected the storage.

thereof; a standpipe on filling andfdispensin I eduction tube connected pf one lot 2,290,839 duit; a vaporizing tank adjacent to the storage tank and connected to receive educted liquid therefrom; a pressure regulator in the liquid eduction conduit for reducing the pressure of the liquid and causing partial vaporization the vaporizing ch'am her; a fitting carried by the standpipe through which vapor is discharged to a point of use; and a valved liquid eduction pipe connected to the fitting and extending into the vaporizing chamber to evacuate separated, normally liquid fuel therefrom for subsequent use. I

3. In a liquefied gas system of the character described, a storage tank adapted to be charged with a mixture of liquefied gas and a normally liquid hydrocarbon fuelto reduce the vapor pressure; a standpipe connected to the tank; valved filling and dispensing appurtenances connected to the standpipe, including a liquid eduction conduit; a vaporizing tank adjacent'to the storage tankand connected to receive educted liquid therefrom; a pressure regulator in the liquid eduction conduit for reducing the pressure of the liquid and causing partial vaporization thereof; a standpipe on the vaporizing chamber; a fitting carried by the standpipe through which vapor is discharged to a point of use; a valved liquid eduction pipe connected to the fitting and extending into the vaporizing chamber to evacuate separated, normally liquid fuel therefrom for subsequent use; and a single protecting casing surrounding both standpipes and the appurtenances thereon. I v

- 4. In a liquefied -gas system of the' character described a storage tank adapted to be charged with a mixture of liquefied gas and a normally liquid hydrocarbon fuel to reduce the vapor pressure; a standpipe connected to the tank; valved v filling and dispensing appurtenances connected to the standpipe, including a liquid eduction con-' duit; va vaporizing tank adjacent to the storage tank and connected to receive educted liquid therefrom; a pressure regulator in the liquid eduction conduit for reducing thepressure of the liquid and causing partial vaporizationthereof; a standpipe on the vaporizing chamber;

vapor is discharged to a point of use; a valved liquid eductionpipe connected to the fitting and drocarbon fuel to reduce the vapor pressure; a-

standpipe connect d to the pressure storage tank -having a combination valved fitting carrying g appurtenances; a liquid to the storage tank through said fitting; a vaporizing tank adjacent to the pressure-storagetank connected to receive liquid discharged therefrom: at least two I pressure reducing regulators inthe liquid eduction tube set to operate at different back pressures to operate in succession and thereby avoid cutting off the supply of liquid due to freezing the regulators; a standpipe on the gauge also carried by 25 moving the separated a fitting carried by the standpipe through which normally liquid use which vapor is deliveredto a point 'of use; a valved liquid eduction pipe connected to said fitting to evacuate lated in the vaporizing chamber; a'liquid level said last named'fitting to determine the level of the separated fuel therein; a gas service pipe connected to said fitting carrying a'second stage pressure reducing regulator;

tenances thereon affording access thereto from above the ground.

6. That method of using propane in a gas dispensing system designed to withstand lower;pressures than the normal vapor pressure of propane,

which comprises charging the system with propane, mixed with commercial gasoline, so that.

ducing the'pressure of the mixture; generating propane vapor by evaporation and simultaneously separating gasoline therefrom at reduced pressure; reducing thepressure'of the vapor and delivering it to a point of use; and periodically regasoline.

7. That method of using propane in a system designed to withstand lower pressures thanthe normal vapor pressure of propane, which consists in mixing thepropane with a readily miscible,

normally liquid'hydrocarbon fuel and thereby reducing-the vapor pressure of the mixture to with- A in the designed working pressure of the system; withdrawing the mixture at a reduced pressure and vaporizing the propane component thereof to separate the normally liquid hydrocarbon component; delivering the vapor to a point of use at a further reduced pressure; a the separated liquid fuel for subsequent use.

8. In a domestic liquefied gas dispensing sys- 40 vte m of the character described, an underground pressure storage tank charged with a mixture of liquefied gas and a readily miscible, normally liquid hydrocarbon .fuel, said mixture having a vapor pressure about the same as that of ordinary butane; a liquid eduction pipe connected to the tank and delivering the mixture, therefrom by virtue ofthe vapor pressure of the mixture in the tank; a separate vaporizing chamber buried in the ground with and connected to receive the educted liquid from the tank; an automatic pressure reducing regulator in the liquid eduction 'pipe'to reduce the pressure of the mixture and permit vaporization of theliquefied gas component of the mixture in the vaporizing chamber; a vapor delivering conduit leading from the vaporizing chamber to a point of use; a pressure reducing regulator in the vapor delivering conduit; and-a liquid eduction pipe connected to,

the'vaporizing chamber to evacuate separated fuel 'there'fromfor subsequent 9. Ina liquefied 'gas dispensing system of the character described, a pressure storage tank adapted to be filled with a mixture of propane and readily miscible normally liquid hydrocarbon fuel; a liquid eduction pipe connected to the tank and delivering the mixture therefrom by virtue of the vapor pressure of the mixture in the tank; a

" separate vaporizing chamber connected to'receive 1 the-educted liquid from the tank: an automatic pressure reducing regulator in the liquid eduction pipe; a vapor delivering conduit leading from the vaporizing chamber to a point of use; a pressure reducing, regulator-in the vapor delivering vaporizing m;- carrying a fitting through lb conduit; a-fitting tedto communicate with separated liquid fuel accumu- V and a single protecting casing sur-. l0 rounding both of said standpipes and the appurand. reclaiming 'the the vaporizing chamber a liquid evacuatingpipe in the vaporizing chamber connected to the ntting; and a valve in the fitting to control the discharge or separated liquid fuel accumulated in vaporizing chamber through said evacuats Pipe- 10. In a liquefledgas system of the character described, wherein a mixture of liquefied gas and gasolineis taken from a storage tank in the liquid phase by virtue 01 its own vapor pressure, a vaporizing chamber connected to receive the discharged liquid and arranged to absorb vaporizing heat for the volatile component of the mixture; automatic pressure reducing means connected to reduce the pressure of the mixture between the tank and the vaporizing chamber; a liquid evacuating tube in charge the separated gasoline accumulated therein: a'ntting carrying a valve connected to the liquid and a hose connection on evacuating tube; tting.

the vaporizing chamber to dis- 11. That method or using propane in a lique- I I fled gas dispensing system designed for a lower vapor pressure than th which is characterized at developed by propane.

by cha ging the pressure p 5 tank oi the system with propane mixed with a readily miscible normally liquid fuel so that the vapor pressure of the designed working mixture is less than-the pressure oi, the system; delivering the mixture under its own vapor pressure 10 to a vaporizing chamber and reducing its pressure in transit; vaporizing the propane by absorption 01' heat in the vaporizing chamber; delivering the propane vapor to a point' 01' use and at a..

further reduced pressure; and periodically re- 15 moving the normally liquid fuel component separated from the mixtur i'orsubsequent use.

e in the vaporizing tanl;

LOYD J. WHITE. 

